Drilling has begun on a North Sea oil field that will eventually support about 700 jobs.

The first oil is expected to be produced from the Mariner field in 2018, Statoil said.

Up to five wells will be drilled using the world's largest jack-up rig before the colossal Mariner A platform is moved into place in next year.

About 500 jobs will be created during the initial six-month drilling phase of the project and another 200 in the long-term.

Statoil Production UK managing director Hedda Felin said: "This is an exciting period for us as a UK continental shelf operator as we transition from the planning phase to active offshore operations.

"Pre-drilling enables production to reach plateau levels more quickly after the start of operations on Mariner A.

"It will also be an important learning period for us in terms of understanding the reservoir and identifying potential efficiencies for future wells, with safety and the protection of the environment being our fundamental priorities."

The Mariner field, which is about 95 miles east of Shetland, is expected to produce oil for about 30 years and up to 100 wells could be drilled over its lifetime.

The field is thought to hold the equivalent of 250 million barrels of oil, which will be extracted at a rate of about 55,000 a day.